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Magnesium Oxide Pure Powder

NOW
4.5
★ ★ ★ ★ ★
(1250 ratings)
Magnesium 290 mg
Product Image
Score79
An inexpensive, clearly dosed powder whose oxide form favors bowel effects over efficient magnesium repletion.
How scoring works
Quantity:8 Liquid(s) • (454 servings)
Goals:
General Health
Energy
Heart Health
Digestive Health
Stress Relief

Score 79

An inexpensive, clearly dosed powder whose oxide form favors bowel effects over efficient magnesium repletion.
How scoring works
$9.50($0.02 per serving)
iHerb
$ 10.40
Daily Vita
$ 9.90
Walmart
$ 13.79
Vitacost
$ 11.17
Pure Formulas
$ 9.50
Report prices

Analysis

The single-ingredient powder is simple and economical, with a meaningful labeled magnesium amount. Flexible measuring may suit people who prefer powder over tablets.

Magnesium oxide is absorbed less efficiently than citrate, glycinate, or malate. It is therefore better suited to users seeking a bowel effect than those prioritizing dependable systemic magnesium support.

The formula contains no supportive cofactors or alternative magnesium forms. Its low cost is useful, but form quality remains the central trade-off.

Who is it for
  • Budget-focused powder users
  • Adults seeking occasional stool-softening support
  • People who can adjust a powder serving carefully
Best for
  • Low-cost magnesium intake
  • Flexible powder dosing
  • Occasional bowel regularity

Pros

  • Very low serving cost
  • Clearly disclosed magnesium amount
  • Focused single-ingredient formula

Cons

  • Oxide has low systemic absorption
  • No complementary nutrients or better-absorbed forms
  • Powder measurement may be less convenient than capsules

Warnings

  • Magnesium oxide may cause loose stools or abdominal cramping
  • Taking too much powder can intensify its laxative effect
  • Impaired kidney function can increase magnesium accumulation risk

Nutrient quality

66 High impact

Magnesium oxide provides the main quality signal, while a meaningful magnesium amount shapes likely usefulness. Absorption, tolerability, and the formula's focus determine the main trade-off.

Ingredient transparency

86 Highest impact

Active amounts are clearly disclosed, and no proprietary blend hides the total formula. Specific ingredient names make the core actives reasonably easy to assess.

Customer satisfaction

85 Highest impact

The high average rating is supported by substantial review volume. No specific review comments are supplied, so repeated complaints and purpose alignment cannot be confirmed directly.

Value for money

82 Highest impact

Value is reasonable for the form quality and disclosed amount. The focused formula avoids paying for token extras, while category competitiveness depends on absorption quality.

Report analysis

Goals

General Health
Stress Resilience
General Health
Impact
High effect
A Goal FitC Strength of SupportD- CoverageA- Formula Quality
Magnesium · 290 mg

Magnesium is a foundational mineral for energy production, muscle function, and nervous-system balance. The powder supplies a meaningful and clearly disclosed elemental amount.

Magnesium oxide is poorly absorbed compared with chelated or citrate forms, which limits systemic benefit. The oxide form may also cause loose stools or abdominal discomfort in sensitive users.

Study evidence
Magnesium Supportive 114 studies
Energy
Energy
Impact
High effect
B Goal FitC- Strength of SupportC- CoverageA- Formula Quality
Magnesium · 290 mg

Magnesium directly supports ATP-dependent metabolism and may help when low intake contributes to fatigue. The elemental amount is substantial and easy to measure.

Magnesium oxide is poorly absorbed compared with citrate or glycinate and may cause gastrointestinal discomfort. The single-ingredient design is focused but covers no alertness or stress-resilience pathway.

Study evidence
Magnesium Supportive 4 studies
Heart Health
Healthy Blood Pressure
Heart Health
Impact
High effect
B Goal FitC Strength of SupportD- CoverageA+ Formula Quality
Magnesium · 290 mg

A meaningful magnesium amount directly supports heart rhythm and vascular tone. The single-mineral powder allows the serving to be measured flexibly.

Magnesium oxide has low systemic absorption and may cause loose stools before delivering dependable mineral support. The formula also lacks lipid, mitochondrial, nitric-oxide, or homocysteine pathways.

Study evidence
Magnesium Supportive 158 studies
Digestive Health
Digestive Health
Impact
High effect
C+ Goal FitC Strength of SupportD CoverageA- Formula Quality
Magnesium · 290 mg

Magnesium oxide can draw water into the bowel and support occasional stool passage. The single-mineral powder provides focused motility support rather than broad digestive care.

The 290 mg amount is clear and likely to affect stool in sensitive users. Loose stools and cramping are possible, and people with significant kidney impairment should avoid unsupervised magnesium use because accumulation can occur.

Study evidence
Magnesium Supportive 50 studies
Stress Relief
Stress Relief
Impact
High effect
B- Goal FitC- Strength of SupportF CoverageA+ Formula Quality
Magnesium · 290 mg

Magnesium provides foundational support for nervous-system regulation and relaxation. Its role is supported by established physiology, with the clearest benefit expected when intake or status is low.

The 290 mg elemental amount falls within a meaningful supplemental range. Magnesium oxide has low systemic absorption despite the exact amount being clear. Magnesium oxide at this amount may cause loose stools or abdominal discomfort while providing limited systemic absorption.

Study evidence
Magnesium Supportive 13 studies
Cardiovascular Support
Cardiovascular Support
Impact
Moderate effect
C+ Goal FitC Strength of SupportD- CoverageA- Formula Quality
Magnesium · 290 mg

A meaningful magnesium amount may support vascular tone when intake is low. The oxide form and single-pathway design are important limits.

Disclosure is complete, but absorption quality is modest. The clean formula contains no padding or broader heart support.

Study evidence
Magnesium Supportive 123 studies

Ingredients

IngredientAmount per serving
Magnesium (Magnesium Oxide)
 290 mg
Gluten Free Adults 18–50 Vegan Dairy Free Vegetarian
Report overview
Magnesium (Magnesium Oxide) · 290 mg OverallScore54
F Active Ingredient Quality & BioavailabilityA Dose, Safety & Label TransparencyC Value

Magnesium oxide has low systemic absorption and may be more likely to cause loose stools than better-absorbed forms. 290 mg of elemental magnesium is clearly disclosed and falls in the standard supplemental range; the clean single-mineral design is simple but adds no uptake or bone-health cofactor. The very low serving cost partly offsets the poorly absorbed form.

View ingredientView products
Loading alternative details
91 Performance

Krebs Magnesium Potassium Complex

Nature's Way
<p>Magnesium lysinate and malate provide favorable forms at a useful 250 mg amount, with 95 mg potassium citrate for broader mineral support. Compared with the original 290 mg amount from Magnesium Oxide, the form disclosure is clearer and the dose is less aggressive for many users.</p>
88 Performance

Magnesium Bisglycinate Powder

NOW
<p>The pure powder provides 250 mg magnesium bisglycinate in a well-absorbed, adjustable form. Compared with the original 290 mg amount from Magnesium Oxide, the single named form is easier to assess and may be gentler on digestion.</p>
85 Performance

Magnesium Bisglycinate Chelate

Healthy Origins
<p>The clean powder uses TRAACS magnesium bisglycinate at a practical 200 mg elemental amount. Compared with the original 290 mg amount from Magnesium Oxide, it prioritizes absorption quality and moderate dosing, although it may provide less total magnesium.</p>
83 Budget

Magnesium Citrate Pure Powder

Best Naturals
<p>No provided candidate is cheaper; the closest low-cost powder provides 210 mg magnesium citrate in an adjustable serving. Compared with the original 290 mg amount from Magnesium Oxide, citrate is clearly identified and generally useful for routine repletion, though it may loosen stools.</p>
80 Budget

Magnesium Caps 500 mg

Life Extension
<p>Another low-cost candidate, though not cheaper than the original, supplies 500 mg magnesium across citrate, succinate, glycinate, and oxide sources. It offers a substantial amount for the cost, but oxide lowers average absorption quality and the high serving may cause diarrhea or cramping compared with the original 290 mg amount from Magnesium Oxide.</p>
84 Budget

Potassium + Magnesium

Nutricost
<p>A third low-cost candidate, though not cheaper than the original, supplies 210 mg magnesium citrate with 99 mg potassium citrate. It offers clear mineral forms and practical value, although its magnesium amount may be lower than the original 290 mg amount from Magnesium Oxide.</p>
85 Value

Magnesium Bisglycinate 200 mg

Natural Factors
<p>The focused powder combines 200 mg magnesium bisglycinate with a moderate serving cost and a nonaggressive dose. Compared with the original 290 mg amount from Magnesium Oxide, the clearly named form improves quality-to-cost balance while reducing the chance of dose-related digestive discomfort.</p>
85 Value

Cal/Mag 500 mg/250 mg

NaturesPlus
<p>The formula pairs 250 mg chelated magnesium with 500 mg chelated calcium in an economical serving. It adds useful bone-mineral breadth and clear forms compared with the original 290 mg amount from Magnesium Oxide, though calcium may be unnecessary for users seeking magnesium alone.</p>
81 Value

Ultra-Mag

Source Naturals
<p>The broad blend supplies 400 mg magnesium from citrate, glycinate, malate, succinate, and taurinate forms at a favorable serving cost. Form diversity improves practical value compared with the original 290 mg amount from Magnesium Oxide, while the high amount and 30 mg vitamin B6 may reduce suitability for long-term routine use.</p>
Report alternatives

Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. Long-term outcome after intravenous magnesium sulphate in suspected acute myocardial infarction: the second Leicester Intravenous Magnesium Intervention Trial (LIMIT-2).
    Woods KL; Fletcher S · Lancet (London, England) · 1994
    Randomized trial2,316 participantsGeneral Health forMagnesium
  2. Hospital-Acquired Dysmagnesemia and In-Hospital Mortality.
    Cheungpasitporn W; Thongprayoon C; Chewcharat A; Petnak T; Mao MA; Davis PW; Bathini T; Vallabhajosyula S; Qureshi F; Erickson SB · Medical sciences (Basel, Switzerland) · 2024
    Cohort study26,020 participantsGeneral Health forMagnesium
  3. A Randomized Double-blind Placebo-controlled Trial on the Effect of Magnesium Oxide in Patients With Chronic Constipation.
    Mori S; Tomita T; Fujimura K; Asano H; Ogawa T; Yamasaki T; Kondo T; Kono T; Tozawa K; Oshima T; Fukui H; Kimura T; Watari J; Miwa H · Journal of neurogastroenterology and motility · 2022
    Randomized trial34 participantsDigestive Health forMagnesium
  4. Diagnosis of magnesium-induced diarrhea.
    Fine KD; Santa Ana CA; Fordtran JS · The New England journal of medicine · 1991
    Clinical trial19 participantsDigestive Health forMagnesium
  5. Association between Serum Magnesium and Fractures: A Systematic Review and Meta-Analysis of Observational Studies.
    Dominguez LJ; Veronese N; Ciriminna S; Pérez-Albela JL; Vásquez-López VF; Rodas-Regalado S; Di Bella G; Parisi A; Tagliaferri F; Barbagallo M · Nutrients · 2023
    Meta-analysis119,755 participants4 studies pooledBone Health forMagnesium
  6. Bioabsorbable Magnesium-Based Materials Potential and Safety in Bone Surgery: A Systematic Review.
    Hung CH; Kwok YC; Yip J; Wong HH; Leung YY · Craniomaxillofacial trauma & reconstruction · 2025
    Systematic review386 participants8 studies pooledBone Health forMagnesium
  7. Vascularized bone grafting fixed by biodegradable magnesium screw for treating osteonecrosis of the femoral head.
    Zhao D; Huang S; Lu F; Wang B; Yang L; Qin L; Yang K; Li Y; Li W; Wang W; Tian S; Zhang X; Gao W; Wang Z; Zhang Y; Xie X; Wang J; Li J · Biomaterials · 2016
    Randomized trial48 participantsBone Health forMagnesium
  8. An update on magnesium and bone health.
    Rondanelli M; Faliva MA; Tartara A; Gasparri C; Perna S; Infantino V; Riva A; Petrangolini G; Peroni G · Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine · 2022
    Narrative reviewBone Health forMagnesium
  9. Sex-specific differences in the association of magnesium intake with femoral neck bone mineral density among older adults.
    Wang B; Tan X; Yao X; Zhu Z · Endocrine connections · 2025
    Cross-sectional study1,343 participantsBone Health forMagnesium
  10. Circulating and dietary magnesium and risk of cardiovascular disease: a systematic review and meta-analysis of prospective studies.
    Del Gobbo LC; Imamura F; Wu JH; de Oliveira Otto MC; Chiuve SE; Mozaffarian D · The American journal of clinical nutrition · 2013
    Meta-analysis313,041 participants16 studies pooledCardiovascular Support forMagnesium
  11. Magnesium and the risk of cardiovascular events: a meta-analysis of prospective cohort studies.
    Qu X; Jin F; Hao Y; Li H; Tang T; Wang H; Yan W; Dai K · PloS one · 2013
    Meta-analysis532,979 participants19 studies pooledCardiovascular Support forMagnesium
  12. Quantitative Association Between Serum/Dietary Magnesium and Cardiovascular Disease/Coronary Heart Disease Risk: A Dose-Response Meta-analysis of Prospective Cohort Studies.
    Zhao L; Hu M; Yang L; Xu H; Song W; Qian Y; Zhao M · Journal of cardiovascular pharmacology · 2020
    Meta-analysis544,581 participants18 studies pooledCardiovascular Support Heart Health forMagnesium
  13. Comparative Efficacy of Nutraceuticals on Endothelial Function: A Systematic Review and Network Meta-Analysis.
    Norouzzadeh M; Rashedi MH; Mahdavi-Mazdeh G; Kosari A; Shahinfar H · Current atherosclerosis reports · 2026
    Meta-analysisCardiovascular Support Heart Health forMagnesium
  14. Serum magnesium, mortality, and cardiovascular disease in chronic kidney disease and end-stage renal disease patients: a systematic review and meta-analysis.
    Xiong J; He T; Wang M; Nie L; Zhang Y; Wang Y; Huang Y; Feng B; Zhang J; Zhao J · Journal of nephrology · 2020
    Meta-analysis200,934 participants20 studies pooledCardiovascular Support forMagnesium
  15. Efficacy of oral magnesium therapy in the treatment of chronic constipation in spastic cerebral palsy children: a randomized controlled trial.
    Hassanein SMA; Deifallah SM; Bastawy HA · World journal of pediatrics : WJP · 2021
    Randomized trial100 participantsDigestive Health forMagnesium
  16. Ca:Mg ratio, medium-chain fatty acids, and the gut microbiome.
    Fan L; Zhu X; Sun S; Yu C; Huang X; Ness R; Dugan LL; Shu L; Seidner DL; Murff HJ; Fodor AA; Azcarate-Peril MA; Shrubsole MJ; Dai Q · Clinical nutrition (Edinburgh, Scotland) · 2022
    Randomized trial240 participantsDigestive Health forMagnesium
  17. The Magnesium-Rich Formula for Functional Constipation in Infants: a Randomized Comparator-Controlled Study.
    Benninga MA; MENA Infant Constipation Study Group; Vandenplas Y · Pediatric gastroenterology, hepatology & nutrition · 2022
    Randomized trial286 participantsDigestive Health forMagnesium
  18. Magnesium treatment increases gut microbiome synthesizing vitamin D and inhibiting colorectal cancer: results from a double-blind precision-based randomized placebo-controlled trial.
    Sun E; Zhu X; Ness RM; Murff HJ; Sun S; Yu C; Fan L; Azcarate-Peril MA; Shrubsole MJ; Dai Q · The American journal of clinical nutrition · 2025
    Randomized trial240 participantsDigestive Health forMagnesium
  19. Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: A randomized controlled trial.
    Hausenblas HA; Lynch T; Hooper S; Shrestha A; Rosendale D; Gu J · Sleep medicine: X · 2025
    Randomized trial80 participantsEnergy forMagnesium
  20. Total magnesium intake and risk of frailty in older women.
    Struijk EA; Fung TT; Bischoff-Ferrari HA; Willett WC; Lopez-Garcia E · Journal of cachexia, sarcopenia and muscle · 2024
    Cohort study81,524 participantsEnergy forMagnesium
  21. Red blood cell magnesium and chronic fatigue syndrome.
    Cox IM; Campbell MJ; Dowson D · Lancet (London, England) · 1991
    Randomized trial32 participantsEnergy forMagnesium
  22. Exercise, magnesium and immune function.
    Laires MJ; Monteiro C · Magnesium research · 2008
    Narrative reviewEnergy forMagnesium
  23. Perioperative systemic magnesium to minimize postoperative pain: a meta-analysis of randomized controlled trials.
    De Oliveira GS; Castro-Alves LJ; Khan JH; McCarthy RJ · Anesthesiology · 2013
    Meta-analysis1,257 participants20 studies pooledGeneral Health forMagnesium
  24. Association of magnesium sulfate use with mortality in critically ill patients with sepsis: a retrospective propensity score-matched cohort study.
    Gu WJ; Duan XJ; Liu XZ; Cen Y; Tao LY; Lyu J; Yin HY · British journal of anaesthesia · 2023
    Cohort study10,999 participantsGeneral Health forMagnesium
  25. Hypomagnesemia and Mortality in Incident Hemodialysis Patients.
    Li L; Streja E; Rhee CM; Mehrotra R; Soohoo M; Brunelli SM; Kovesdy CP; Kalantar-Zadeh K · American journal of kidney diseases : the official journal of the National Kidney Foundation · 2016
    Cohort study9,359 participantsGeneral Health forMagnesium
  26. The effects of magnesium supplementation on abnormal uterine bleeding, alopecia, quality of life, and acne in women with polycystic ovary syndrome: a randomized clinical trial.
    Jaripur M; Ghasemi-Tehrani H; Askari G; Gholizadeh-Moghaddam M; Clark CCT; Rouhani MH · Reproductive biology and endocrinology : RB&E · 2022
    Randomized trial64 participantsGeneral Health forMagnesium
  27. Effects of magnesium supplementation on improving hyperglycemia, hypercholesterolemia, and hypertension in type 2 diabetes: A pooled analysis of 24 randomized controlled trials.
    Xu L; Li X; Wang X; Xu M · Frontiers in nutrition · 2023
    Meta-analysis1,325 participants24 studies pooledHeart Health forMagnesium
  28. The effect of lowering blood pressure by magnesium supplementation in diabetic hypertensive adults with low serum magnesium levels: a randomized, double-blind, placebo-controlled clinical trial.
    Guerrero-Romero F; Rodríguez-Morán M · Journal of human hypertension · 2009
    Randomized trial82 participantsHeart Health forMagnesium
  29. Positive effects of magnesium supplementation in metabolic syndrome.
    Kisters S; Kisters K; Werner T; Vormann J; Tokmak F; Westhoff T; Gröber U; Predel HG; Reuter H · International journal of clinical pharmacology and therapeutics · 2024
    Randomized trial54 participantsHeart Health forMagnesium
  30. Role of magnesium supplementation in the treatment of depression: A randomized clinical trial.
    Tarleton EK; Littenberg B; MacLean CD; Kennedy AG; Daley C · PloS one · 2017
    Randomized trial126 participantsStress Relief forMagnesium
  31. Effects of Intravenous Esketamine or Magnesium Sulfate on Early Postoperative Negative Emotions and Pain in Patients Undergoing Endoscopic Sinus Surgery: A Randomized Controlled Trial.
    Wang L; Zhou J; Liu Q; Qian K; Wang L; Xie C · Therapeutics and clinical risk management · 2026
    Randomized trial137 participantsStress Relief forMagnesium
  32. Effect of short-term magnesium supplementation on anxiety, depression and sleep quality in patients after open-heart surgery.
    Saba S; Faizi F; Sepandi M; Nehrir B · Magnesium research · 2022
    Non-randomized trial60 participantsStress Relief forMagnesium
  33. Effects of dry needling compared to magnesium infiltration in trigger points for patients with myofascial pain syndrome: a randomized controlled study in Tunisia.
    Dhouibi J; Moncer R; Kalbousi N; Gaddour M; Laayouni S; Ouanes W; Kacem B; Jemni S · Korean journal of family medicine · 2026
    Randomized trial45 participantsStress Relief forMagnesium
  34. Effect of magnesium and vitamin B6 supplementation on mental health and quality of life in stressed healthy adults: Post-hoc analysis of a randomised controlled trial.
    Noah L; Dye L; Bois De Fer B; Mazur A; Pickering G; Pouteau E · Stress and health : journal of the International Society for the Investigation of Stress · 2021
    Randomized trialStress Relief forMagnesium
  35. Magnesium and anabolic hormones in older men.
    Maggio M; Ceda GP; Lauretani F; Cattabiani C; Avantaggiato E; Morganti S; Ablondi F; Bandinelli S; Dominguez LJ; Barbagallo M; Paolisso G; Semba RD; Ferrucci L · International journal of andrology · 2012
    Cohort study399 participantsTestosterone Support forMagnesium
  36. Analysis of the relationship between the blood concentration of several metals, macro- and micronutrients and endocrine disorders associated with male aging.
    Rotter I; Kosik-Bogacka DI; Dołęgowska B; Safranow K; Kuczyńska M; Laszczyńska M · Environmental geochemistry and health · 2017
    Cross-sectional study313 participantsTestosterone Support forMagnesium
  37. Effect of magnesium supplementation in improving hyperandrogenism, hirsutism, and sleep quality in women with polycystic ovary syndrome: A randomized, placebo-controlled clinical trial.
    Gholizadeh-Moghaddam M; Ghasemi-Tehrani H; Askari G; Jaripur M; Clark CCT; Rouhani MH · Health science reports · 2024
    Randomized trial64 participantsTestosterone Support forMagnesium
  38. The effects of trace element supplementation on glycolipid metabolism in PCOS: a systematic review and meta-analysis.
    Yang L; Gao Y; Zhao W; Qi Y; Duo X; Wang H · Frontiers in nutrition · 2025
    Meta-analysis1,600 participants25 studies pooledTestosterone Support forMagnesium
  39. Effects of magnesium supplementation on testosterone levels of athletes and sedentary subjects at rest and after exhaustion.
    Cinar V; Polat Y; Baltaci AK; Mogulkoc R · Biological trace element research · 2011
    Non-randomized trial20 participantsTestosterone Support forMagnesium